Spontaneous ureterocele wall rupture by a ureteral stone: A case report

Abstract

Ureterocele, a type of ectopic ureter characterized by cystic dilation of the distal ureter, can sometimes contain stones. Here, we present the case of a 67-year-old woman who was under observation for ureteral stone and experienced spontaneous ureterocele wall ruptured due to the stone. As illustrated in the present case, conservative observation, which is recommended as initial management of stones in ureterocele to reduce the risk of vesicoureteral reflux following transurethral ureterocele incision, may be associated with increased risk of ureterocele wall rupture and subsequent vesicoureteral reflux.

1. Introduction

Ureteroceles, which are a type of ectopic ureter characterized by cystic dilation of the distal ureter, arise from the failure of Chwalle's membrane at the ureteral orifice to regress before birth. The reported incidence of ureterocele is 1/1000–1/4000 children.¹ Ureterocele with minimal dilation and mild/absent upper urinary tract dilation may be observed in adults, and long-standing ureteral stones may be found in these ureteroceles. Here, we report the case of a patient with a ureterocele that spontaneously ruptured by a ureteral stone.

2. Case presentation

A 67-year-old woman, who was diagnosed with an asymptomatic 1.0 × 0.9 cm ureteral stone in the right intravesical single-system ureterocele without hydronephrosis by magnetic resonance imaging and computed tomography for 6 years, noticed gross hematuria for one week and presented with pollakiuria and dysuria (Fig. 1). She denied colicky pain. Pollakiuria and dysuria persisted despite the disappearance of gross hematuria. At the time of consultation, urinary analysis revealed mild microscopic hematuria without pyuria, and her serum creatinine and hemoglobin levels were within the normal range. Computed tomography scan revealed a stone, 1.5 × 1.3 cm in size, in the bladder and no signs of hydronephrosis. Cystoscopic examination revealed the stone and ruptured right ureterocele wall (Fig. 2). These findings suggested spontaneous rupture of the ureterocele by the stone that traveled from the ureterocele to the bladder, giving rise to the lower urinary tract symptoms.

Fig. 1.

Magnetic resonance imaging six years before ureterocele wall rupture showing a stone, 1.0× 0.9 cm in size, in the right intravesical ureterocele (arrow). There is no evidence of hydronephrosis or duplex collecting system. Note that the size of the stone increased at the time of rupture.

Fig. 2.

Intraoperative cystoscopic images. (A) Stone observed in the bladder. (B, C) Ruptured right ureterocele. The original orifice is detected on the ureterocele wall (arrow) away from the ruptured section.

Transurethral vesicolithotripsy with a holmium laser was performed. During the operation, the right ureteral orifice was observed on the ureterocele wall away from the ruptured section. Postoperative analysis indicated that the stone was composed of calcium oxalate. Lower urinary tract symptoms completely resolved immediately after the operation. At follow-up evaluation six months after the operation, there was no evidence of hydronephrosis or abnormalities in urinalysis and blood tests to suggest vesicoureteral reflux.

3. Discussion

Stones in ureteroceles, which are reported in 4%–39% of patients with ureteroceles,² might transit through the ureteral orifice; therefore, conservative observation is recommended as initial management for stones in ureteroceles.³ However, in some cases spontaneous stone expulsion from the ureteric orifice of the ureterocele is difficult due to the small opening. Therefore, aggressive medical intervention is necessary in symptomatic patients and in those at high risk of organ dysfunction.⁴ In contrast, long-standing stones in ureteroceles can cause ischemia, pressure necrosis, and erosion of the ureterocele wall,⁵ which might induce spontaneous rupture of the ureterocele.

To date, only one case of spontaneous ureterocele rupture caused by a ureteral stone has been published in an English journal.¹ The patient had a 2.0-cm stone that eroded the ureterocele wall and impacted in the urethra, causing dysuria. The patient presented to the hospital after the emergence of symptoms; therefore, imaging studies confirming that the stone was in the ureterocele prior to the rupture were not available. In the present case, the rupture occurred during conservative observation. The patient was evaluated using magnetic resonance imaging, computed tomography, and cystoscopy before and after the rupture, which confirmed spontaneous ureterocele rupture. Incidentally, a previous study reported a case where ureterocele wall erosion by a ureteral stone was treated before the stone's passage to the bladder,⁵ suggesting that prolonged observation could have led to the subsequent observation of spontaneous ureterocele wall rupture, similar to that occurred in the present case. The incidence of spontaneous ureterocele wall rupture by a ureteral stone is unknown; however, this possibility should be considered in patients with stones in ureterocele.

Ureterocele wall rupture is mechanistically similar to post-transurethral incision of the ureterocele. Therefore, patients who experience spontaneous rupture of the ureterocele wall may also develop vesicoureteral reflux, which is a common complication of the transurethral incision of ureterocele. While observation is recommended to prevent the risk of subsequent vesicoureteral reflux after the transurethral incision in these patients,³ the risk of vesicoureteral reflux due to spontaneous rupture should be considered during follow-up of patients with stones in ureterocele.

4. Conclusion

Stones in ureterocele may lead to ureterocele wall rupture, leading to vesicoureteral reflux. Careful follow-up is recommended in patients with ureterocele containing stones, including those who are asymptomatic, while taking the risk of rupture into consideration.

Consent

Written consent was obtained from the patient.

Funding

None.

Declaration of competing interest

None.